The demolition of one of the oldest churches in Canterbury has been branded an "absolute sacrilege" by heritage advocates, but Anglican Bishop Victoria Matthews is defending the deconstruction of the quake-damaged Church of the Holy Trinity.

The Avonside building, designed by Benjamin Mountfort and consecrated in 1857, was badly damaged in the February 22 earthquake and has now been almost completely demolished.

Lyttelton sculptor and stonemason Mark Whyte and heritage advocate Lorraine North, however, say the church should have been slowly deconstructed in order to salvage unique heritage materials.

Whyte said the building, with unique stained-glass windows and hand-painted ceilings, was more important than Christ Church Cathedral.

"It is a pile of smashed up timbers now. It is absolute sacrilege," he said. "It is a very important church and has some very important Mountfort ceilings that have all been smashed in.

"In a perfect world, I would have very slowly dismantled the place and retrieved as much as possible of the heritage fabric, but it is all gone. It is pretty sad.

"The ceilings had collapsed, but it really doesn't help being demolished in this way. It could've been picked over by hand rather than the diggers crunching over them.

"This is indicative of what is happening in Christchurch on every heritage site.

"It's a knee-jerk reaction.

"This is hugely frustrating."

North said the demolition had been "too hasty" and it was "a shame that other options were not explored and there was no public appeal and no attempt to save the church without just going to demolition.

"It is a very great loss."

Bishop Matthews, however, said the church had been a "very, very perilous building".

"It was a beautiful building, but my priority has to be humans and the safety of the community. It wasn't a time to take chances."

Project manager Kevin Long said workers had recovered as much of the heritage fabric as possible. A stone font, pulpit steps and a series of stone carvings were salvaged, as was a time capsule – a glass bottle set in concrete beneath the nave and containing a piece of paper with the words of the church's original consecration.

"We are pretty lucky to have recovered what we are recovering, because a lot of it didn't survive," Long said. "We will carry on recovering as much as we can." Fairfax NZ